I appreciate your comments.
Well, one odd example does not interest me. When I start to see a pattern, then I have an interest.
I can come up with several reasons why it maybe “domed”, but I am pretty confident it is not factory. That modification would actually interfere with the lower valence. On the outside chance it is factory, I dont believe it was intended to be that way.
Perhaps the fog light nuts were overtightened at some point? I would give it a little more weight if you are the original owner and the car has never been apart, but again, I dont see any reason the distortion would have a benefit....
Is the picture posted above a second example? If so, the distortion may have been caused by stamping the hole? If it were mine, I would probably get a big hammer and fix it.